Muzzle closure device for guns



April 6, 1948. A. E. KRAMER 'ETAL "12,438,924

MUZZLE CLOSURE DEVICE FOR GUNS Filed Oct. 50, 1946 4 Sheets-Sheet 1 April 6, 1948. A. E. KRAMER ETAL `MUZZLE CLOSURE DEVICE FOR GUNS 4 Sheets-Sheet 2 Filed Oct. 50, 1946 MMA www Alexnder E. Krmel* Vlcrnv Fl LuEl-t Inn-IJ 4 `Sheets-Sheet 3 mu/y A. E. KRAMER ETAI.

MUZZLE CLOSURE DEVICE FOR GUNS Filed Oct. 50, 1946 April 6,1948.

April 6, 1948.

A. E. KRAMER VErm.

MUZZLE CLOSURE DEVICE FOR GUNS 4 sheets-sheet 4 Filed oct. so, 1946 A] exu1-ldap E Krul-nel VincnPFl Lluch?. m/MLWZMJM,

Patented Apr. 6, 194g 2,438,924 MUZZLE CLOSURE DEVICE FOR GUNS Alexander E. Kramer, Hyattsville, Md., and y Victor F. Lucht, Washington, D.C.

Application October 30, 1946, Serial'No. 706,786

17 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 1 'Ihe invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon;

This invention relates to a muzzle closure device for guns, particularly those of the type mounted on a vehicle and equipped with a recoil mechanism having as a part thereof a hydraulic system.

This type is usually mounted in, but not necessarily limited to, a vehicle such as a plane, tank or armored car. The gun may be fired by a remote control device actuated by either the pilot, the vehicle operator or eby some other member of the crew and may be loaded manually or by some other method. 15

A considerableamount of the propellent gases, products of the explosion and toxic in effect, have a tendency to remain in the gun barrel after firing. As a result, when the projectile leaves the gun barrel there is an inrush of air which, ac-

centuated by the motion of the vehicle, will force these gases back through the breech, as it is being opened preparatory to ejecting the red round and receiving a new one, and enter the gun com- Inview of the confining nature and the enclosed space of these vehicles, the presence of the toxic gases'is objectionable and often injurious to the occupants of the vehicles to the extent that they may become incapacitated to perform their 30 duties. 1

Furthermore, when the gun is mounted in the nose of a plane or on some other rapidly moving vehicle, the wind pressure in the gun barrel will,

at times, be suiiiciently great either to prevent the loading of the gun or to force a round of ammunition out of the breech recess. This in turn requires that considerable force be exerted upon the shell in order to shove it home in the gun chamber and trip the extractors to close the breechblock and consequently places an undue strain upon any individual attempting to load the gun or upon any mechanical loading equipment. Y

The object of the inventionis 'to provide `a cover or shield device that will function upon the leaving of a projectile from the gun barrel to close or cover its muzzle end to minimize the effect of wind pressure and thus prevent the grun powder fumes from being blown back throughthe open breech recess and also facilitate the insertion of A still additional object is to provide a muzzle closure device that willnot materially alect space and Weight requirements which are limited in vehicles. Y Y

Incidental objects tothe above, particularly during storage of the weapon or during inactive periods, is to protect the bore' of the gun barrel against injury from moisture, .accumulation of dirt, or entry ofany foreign matter.

The foregoing and other objects of the invention will become apparent by reference to the specication and attached drawings in which:

Figure 1 is a plan view of the muzzle closure device attached to a gun, the. device being shown in open position prior to the ring of the gun;

Figure 2 is a side elevational view of Figure 1 with the addition of a schematic showing 0i the electrical circuits involved;

Figure 3 is a fragmentary vertical longitudinal sectional view taken through line 3--3'of Figure 1 but showing the muzzle closure device in a closed position to cover the grun muzzle;

Figure 4 is a fragmentary` horizontal-longitudinal section taken through line 4-4 of Figure 3; `partment as well as other portions of the vehicle. 25

Figure 5 is a vertical longitudinal sectional view of the oil-actuated power cylinder for operating the closure device and is taken through line 5--5 Figures 1 and 6; v c

Figure 6 is a vertical transverse section through line 6 6 of Figures 1 and rshowing details of the actuating mechanism for the closure device;

Figure 7 is a fragmentary view taken through line 'l-'l of Figure 6 showing details of the oneway friction brake mechanism; Y Y

Figure is a vertical longitudinal sectional view through lineV 8--8 of Figure 1 showing details of the exible connection between the driving piston rod, actuated by the mechanism of Figure 5, and the driven .concentric front tube carrying closure members; Y

Figures 9, 10, 11 and 12 are schematic wiring diagrams showing the relationship between the various electrical components and the parts of the muzzle closure device during different stages in the cycle of operation involved between the liring of the gun and the functioning of the muzzle closure device; Y Y

Figure 13 is an enlarged fragmentary top View of 'Figure 1 showing the manner of cooperation between the crank cam, the; breech-operating crank and the single-pole switch; and

Figure 14 is an elevational view taken through lines Ill-I4 of Figure .13 showing the breechoperating crank in positions corresponding to those inustratea in Figures 9, 1o, 11 and 12.

'The invention is applied to a gun which, as shown in Figures 1 and 2, is equipped with a stationary cradle tube l, a gun barrel 2 slidably mounted therein, a breech mechanism 3 containing a breech block 3', a stationary recoil guide 4, a breechoperatingpnank 5 and .an electricallyoperated `device energized .by .a r'handoperated ring switch 1. A signal light 9 is connected in parallel with the switch 'I and a rillg solenoid 8. When the light .9 .is illuminated, it 19 indicates that the breech block 3" -has been closed and the gun is ready for firing.

The stationary cradle tube i is pivotally positioned through a pair of diametrically positioned trunnions l in a suitable stationary support of the vehicle. The stationary cradle tube -I houses a combined hydraulic and spring recoil mechanism generally indicated by referencelnumeral H mounted coaxially about the gunbarrel f2. This type of hydrospring recoil mechanism may be .Similar fto .that described in :.RatentZNo. 2,358,340', :issued :September 19, 119.4=,1.f.orrRecoil mechanism. The stationary'frecoil l'guide '4 is fastened .tozthe right rear side of the cradle tube l and cooperates with fthe .gunfbarrel Zzto prevent .rotation .thereof during ".ring. Themecoilfguide .'13 as shown more clearly in Figures 1.-3-;and :L4 has pivoted thereon a .cam lever .12 .spring pressed ,towards .the .breech of the gun by 'an :enclosed spring L3. The cam -lever 1|.2 has .an arm .M provided vwith a horizon- .tal ledge |15fand-ataperedsurface 1&6 adjacent to and .albovettheiledge i5. `iCoopera-ting with the .camlever 12 is aibreech-nperatingcrank'15 having a -beveliledcrankpin 'The breech-operating crank is vfastened `to the rbneech-operatingshait Lil which, through a breech-,blockerari'kmotshown, causes the breechblock 3' to rise (close) Gr.drop (open) in `a' manner .Well known '.to the nrtand 1the vdetails th ereof form .n.0 .part of cthe present invention.

The .ringfswitch l .which-vis usually Vlocated at a distance from lthegnn and .when-closed energizes .thefring solenoidaofzthe vfir-ing mechanism .6 which fin :turn actuates :aring .pin in .the .conventionalimanner.

'Whenpthe gunrisfflred, yit Wilrlxrecoilto the Vrear .carrying with itthebreeclnmechanism 3,1including the breech-operating crank in a substantially vertical `position, :causing the .fend .of the crank pin 'thereof Ato .ride ...along and bear against the tanered .surface it Aof the varm .-Il, pushing it aside tagainst the Iaction of the .compression spring 4&3 euntilithe crank pine' vrides off the lever end |1'l,:.a-s.-.shown byposition B in Figur-.es :1.0 and :114, whereupon the lever t2 will bereturned .toits original .position by the spring .13.

:Upon :completion .of it'he :recoil movement, the gun :will irbe returned 'forwar-dly vin -counterrecoil at battery position by the recoil mechanism H. With `this iforwarmmovement, thecrank J5 is .also carried `to :the 'front l.with the breech mechanism 3, but during :this forward amovem'ent, .the crank pin =5' will strike 'the 'lever .end Il .as shown by position-16min' Figure 14,.andibe revolved thereby 'in la .clockwise .direction .to the substantially horizontal position shown as positionv C in Figures 1`l .and Y14 Aand lbe :held 'in that revolved position 4against :return in -:the opposite -direction by the under `surface of -the ledge AI5 during further forward :movement :in Vcounterrecoil by the gun. yThis clockwise .rotation .of the .crank pin 5' willlcausethe shaft 11.8 to drop (open) the breechblcck 13 which Pin turn will .actnate the extractor devices, shown, within 'the breech 4 mechanism 3 to extract the spent empty case and lock the breechblock 3 in its down (open) position and thus retain the crank pin 5 substantially horizontal, but as the counterrecoil movement is completed, the crank y5 will clear the Ileolgerla.

VWhen .anew `:round is vthrown -into the breech, it will rock the extractor devices to unlock the -breechblock 3', whereupon a spring assembly, generallyindicated by the reference numeral 6',

will -raise (close) the breechblock 3' and return the crank :5 in -a -counterclockwise movement to :its ,Original substantially Vertical position, as

shown ,in Figures .12 and 14, as position D ypreparatory to ridi-ng against the tapered surface t6 whenrthe gun again recoils.

As explained in-Patent No. 2,358,340 a recoil cylinder 11S is ffastened directly to and therefore Ymoves with the barrel v2. The cylinder I9 slides between the inner concentric sleeve 20 and the other .tube .l attached .to .the .trunnions ill. 'The Linnenisleeve it) and .tube l :are Arigidily secured together and form an elongated annular Lchamber containing the hydraulic .and Aspring .mechanism `of therecoil system. ,1A -lin'er2zl iis added to 'the tube :I to :provide rigidity and .strength .for

vthesame.

When .the .gun is fired, recoil :action will carry ther'ecoil piston cylinder Llbackwardly torcing oil .of thehydraulicmechanism toithelrear of the lchamber provided between @the sleeve .Zlland Lthe tube i .to cushion :theshock-of -recoil :in the manner .described in .the patentz-mentioned-above.

The .mechanism .and .elements Athus far de' scribed relate to parts usually :found onlweapons ofthe type imentioned Vand :form y:no :part .of 4our invention. Theyftherefore have Ibeen only-generally `illustrated and briefly described to indicate the `application .of the invention. Further -description ,ofzthese parts .will 'henceforthbe :limited to .their manner @f coopera'tion'with.thefvarious parts .of rvthe invention ito .be fnow explained-.in ldetail.

A single-throw .switch:22, 'having ra push but- .ton 213, is .attached nto :the Vstationary .recoil iguide E4 .and in the :path .of movement of the ,breech `.Oper-ating crank :arm :5. The .push lbutton 123 is operated 'by ithe crank ,arm 5 ".to close .the .switch 2,2 :when theguniis in battery lposition, as vshown in Figures 119 and 14, .and .open the .switch 22 when the gun is moved rearwardly in recoil-carrying With `it zthe Acrank i5, as .shown .by .Figures 10 kand, Y1.4, all-for .a purpose to be described.

A quantity 'of @thepil in zthe annular chamber between sleeve 2;@ fand `tube forced .tothe rear as the cylinder t9 -moves :recoil :with the :gun barrel 2, willbe fed through 'an elbow tting :24 to a pipe .2.5 which isfcennectedby a .conventional 'Coupling -216 to v.a .ribbed oil cylinder .21 through a throttle 'valve ..255 containing .a .screw-threaded member .2e .preperbrsealedat-,againstzoi leakage. movement ofgthe member 2.9 in or zent re1- ative t0 the passae :3.4. regulatingfithe',oilnressure in ther-Oil cylinder legali-1st .ariston *32 attached to a piston rod t,

The cil `lcylinder 2:1 is aliassen 4at fikfor .attachment through bolts A35 to 'a'flaznee 1.85 `ci a spring Cylinder 31.

i Rearward movement of thjnlarged piston 38- isflimited by the oil cylinderv flange 34 and forward movement by a longitudinally extending sleeveV 42 projectingfrom a -forward cylinder head43 and surrounding the Velongated rod 39, the shock-absorbing material 40 and 4l cooperating with their respective stops 34 and 42 to eliminate shock and jarring of parts.

-A compression spring' 44 within the spring cylinder 31 opposes movement of theV piston 38 and also functions to return the same to its battery position shown in Figure 5. 'Ihe spring 44 has its ends seated on the annular flange 45 of the cylinder head 43 and the annular iiange 46 of thepiston 38. -i i vAV double-throw switch 41 is mounted on the oil Acylinder frame 21, and 'is 'provided with an operating rod 48 Yslidably guided in the cylinder flange 34 for contacting and actuation by the enlarged piston 38.

The forward cylinder-head 43 is provided with a friction brake housing 49 having an outboard bearing 49', an annular stepped recess 59, channel-shaped grooves I and 52 and a rounded pro-y jection l53 in the slot 52.

A one-way brake device 54 is enclosed bythe housing 49 and consists of a series of abutting metallic plates 55 and 56. Each Iplate 55, as shown in end view of Figure 6, is substantially circular and provided with diametrically opposite tongue portions 51 slidably received in the slots 5I` andv 52, anda central aperture 58 having a -diameter slightly larger than that of the rod 39, forloosely receiving the same thus permitting the plates to tilt relative to the rod 39.

- 'I'he end plate 56 of the one-Way brake device 54 has a configuration similar to that of plates 55 with the exception that the plate r56 is substantially thicker `than the plates 55 and has one of its tongue portions extended through and guided by a slot 60 in the groove 5l to form a lever-arm l59 for actuating the one-way friction brake. The lever arm 59 is provided at one end thereof with an adjustable screw stop 60' contacting a solenoid plunger 6I actuated by a solenoid 62 carried by the air cylinder 31.

The outboard bearing+49 slidably supports the reciprocating rod 39 which in turn slidably carries a collar 63 provided with a conc-ave surface 64 and forced by a compression spring 65 within the recess 59 against the friction plates 55 and As 4shown `in Figure '7, the projection 53 functions as a pivot for the friction plates Vand is slightly forward ofthe solenoid plunger 6| when the solenoid 62 is deenergized, as a result of which the friction plates 55 and 56 are caused to assume a tilted position by the spring-pressed collar 63 and thus grip the rod 39 against movement of the same to the rear of the weapon, or to the right when viewed in Figure 7.

When the elongated rod 39 is moved in a direction toward the muzzle end of the weapon ,(to

in a reverse direction to the rear (to the right in Figure '1) .thefriction between the rod39 and the plate openings 58, assisted by the springpressed collar 63, -will cause the plates 55 and 56 to be tilted about the projection 53 against the solenoid plunger 6l to grip the rod `39 against any further rearward motion.

Y During the proper interval in the operation cylo'le, to be explained later, when the solenoid 62 is energized, the solenoid plunger 6| is forced outwardly against the lever arm 59 causing the friction plates 55 and 56 to move or tiit counterclockwise, when viewed in Figure 7, about the projection 53 and against the surface 64 of the spring-pressed collar 63 to release the elongated rod 39 for rearward movement to battery position, shown in Figure 5, by the spring 44 acting against' the piston 33 rigidly secured to the rod 39.

The forward portion of the piston rod 39, .as shown in Figure 8, has a reduced threaded portion 65 for receiving a anged sleeve 66 locked in place by a nut 61. An elongated rubber sleeve 68 is bonded to concentric metallic bushings 69 and 19. The inner bushing 69 is locked on the sleeve 66 between its flange 66 and the nut 61. The outer bushing is secured in a housing 1l against its shoulder-1l by a threaded cap 12.

The `housing 1I is rigidly attached Vto areciprocating concentric front tube 13, the rear end fof which is sli-dabiy mounted on the concentric gun cover tube 1'4 and the forward end of Which'isprovided with a web 15 carrying an internal concentric bearing' surface 16 slidable upon a blast tube 11. The bearing surface 16 is cut away at 18 to provide the necessary clearance for pairs of hinge arms 19 pivoted on pins 88 anchored on the front tube 13. The blast tube 'i1 is concentric with the gun barrel 2 and is'attached by bolts 8| to the stationary tube 26. The blast tube 11 in addition to serving as a support for the surface 16, protects the muzzle closure device and associated parts from injury and possible destruction by the blast of the propelilent gases leaving the muzzle end of the barrel, which exert a tremendous pressure for a relative short distance about the muzzle end of the gun .until dissipated in the atmosphere.

To close the muzzle end of the gun barrel 2 against the iniush of air a pair of members or petals -82 is employed, each substantially of clamshell bucket shape,as shown, and biased by spaced'springs 83 toward each other to a lclosing position as shown4 in Figures 3 and 4.

A' pair of the hinge arms 19 is attached to each petal 82 and thusthe .latterare oscillatable on the pivot pins 88 anchored to the reciprocable concentricfront tube 13. A gear segment 84 is formed integral with each hinge arm 19 and those gear segments 84 on the same side of 'the front tube 13 are i-n mesh with each other thereby causing the petals 82 to rotate to an open or closed position in lunlison with each other. Also, the Weight of one petal 82, is thereby counterbalancedby the weight of the other.

'Internally secured to each petal is` an inclined pad 85. When the piston rod 39 pulls the-front tube v13 to the rear, the petals 82 carried thereby will also be moved back and as they so move, the incline pads 85 will be compelled to ride on and over the ysurfaceil6 of the blast tube 11 thereby causing the petals 82 to be spread apart, as 'shown in Figure 2, against the action of the springs 83 by extending the same, exposing the muzzleopening and providing an unobstructed passage for a projectile to be fired in the customary manner. When the piston rod 39 pushes the tube.-13 .tol the front, thelpads 85 will lride oi thev surface .86 allowing the springs; 8'3 to: bring; the petals together.` and therelui coter; the muzzle.A opening; against; air rushing` in; through theA gun barrer 2. which turni would have forced the residuali toxic-gases; bach. through the gun Ibarrel and. out: the'. breech. into. the vehicle compartment with. injurious. results. to; in:- dividuals the cormaartrnent.r

The electrical circuit is; energicedsby any suitable source oli; energy 8S." which. hows.. through the singlefthrcw switch 2.2v and lead.y 8l. to; the; double-throwswitch. 415 to; alternatively activate the circuit 8.8 through contacts:E tlfY or. circuit, 39 through contacts: 41..

Operation- The muzzle closure .device operates in timed: relation with the breechblofcls- 3f so that when the salme is down (open), theepetals 82, are closed to cover or bloclr` the: muzzle end. ot the barrel 2 toprevent the'residual; gasesitroin beingI forced back through the openedbreech by, in;- rushing air. Conversely, when the breech; block 3' is up (closed) preparatory to.ring-,-the; petals 82 will uncover and clear the muzzle; end of thegun to permit free passage. of theprojectile;

Figure 9- schematicout;v illustrates; the parte at the beginning ot the operation cycle, Asa shown-v in this ligure; the gunv is. in battery position, loaded, the muzzle cover-is moanedy and thefbrcechblock 3 is up (closedo placing the breeeheoper, ating crank 5 in. a substantially. vertical position (position A) resting; against. the push bui-,ton` 23V closing; the` switch 2-2=.4 Also; the piston 38; at.- tached to the. rod 39 is inits rearmost position'. inthe air cylinder- 3.1, as shown also in Figure. 5.-..

contactingY the push rodi 48 off. the dollblf'thzlO-W' switch li'l toy close oneset of contacts. 411 illuminating theY sign-al light 9: and energizing the circuit having` the firing switch 1^. With: pistoni 3s as. shown in. Figure ,5i thereto-1s, 8:2: aroopened.. asin Figures 1 and 2, theclut.ch-release.;solenoidI 62 is deenergizedand the friction: plates: iii2 and 5e tilted by the spring-pressed collar 63.- as shown', in Figure 7.

Referring to Figure 1-0v forthe.l nextstagei in, the operation cycle. when the ring. switch l; is closed*y thev iring solenoid 8: actuates; they iiiimg; mechanism 6 trippingthe. necessary mechanism for releasing the. firing. nin against the primer of a round of ammunition -toiirethe ,saineE The gun will recoily to the rear carrying with it: the breech-operating crank 5 from its position A to position B, away trono. the. push button 2.3: of the switch 2.2.. to open the: same, thus breaking the owof current fromthe; source 8.6. rendering the electrical circuits.. 8.1:, 881' and B3. inoscrambleV and also extinguishing' the sign-al. light. 9i,

Movement of; the gun tothe; rear in recoiliwill result in the recoil` mechanism; forcing aouantity of its oil through the. tube. 2i against. the small: piston 32, which in turn will; cause the. enlarged piston 38 and its piston roelA 39; muzzle-wards, releasing the push. rod. 48: ofthe switch. 41115 permitting the same to yclose at lcontacts 41, preparatory for the next. stage in the operation. cycle;` schematically shown in Figure 1111,` ande also; shifting the outer front tubey 135 tocausethe petalpads 35 to ride off the. blast tube. surfaces, 86; thereby` permitting the petals. 8.2: to. close oi the muzzle from, the inrushing. air. Also, the. breech oper.- ating crank 5 will be moved. to, the rear with the weapon causing its, crank pin 5' to slide. against. the tapered surface. |16', pushing aside the lever arm I4 and riding. orfits endv i7.

When movementof the guny .rearwardly in re.-

8 coil. hasbeen. completed and forward movement in'v countcrrecoill is about to, begin, the breechonerating; crank. arm 5l will strike the end; |51 and be rotated,- clockwise, as; shown by 'position C inrFigure 14,to a.. substantially lmrizontal position., position; (2, todropv (fopen) the.- breechblock 3 and. eject the fired round-, and at the same time the oil Ipressure in the tube 25 will subside; However,` due to the holding action of the; friction plates and 56V, the rod 3,9, will be held' in its, forward position and; retain the petals 82v closed.

The. placing of a new round or ammunition into the gun chamber will. activate the extractor devices to permit thebreech closinggdevice 6- to lift (close) the breechblock 3 rotatingthev breech operating crank 5 to a substantially vertical; position, position. D closing the switch 22: assche.- matlcallv shown in Figure. 12;v and also; in; Figure. 14.V

Closing of the switch 22 will, causo current to 'ow from the source 86, through 311', contact-,5,1411 to; energize the clutch-brake solenoid: 6.2v forcing: the solenoid! plunger al: against the lever. armi 59., tilting the friction plates 55 and. 56 in acouIl-EF- clockwise direction to releasel the rod 38; and-pis,- ton 38, for return movement to battery psiton by the spring. 44.. When they piston 38 reaches battery position, it will operate push rodi 18 toopen-.switch f' at 4l and' close it at 4'1"' 001.11-l pl'eting the. cycle,

Under normal.. circumstances, when the gun isloadedA and ready tonite, the petals 82 are opened.

and remain: sonntilz the gun is fired. Conversely.. after the gunhas been fired, the; petalsy 8.2: are closed and the` breech; openedthe, parte romaine ing in these/relative; positions until anew round has' been rammed intoplace.

However, there may be. times when it isA desir-V able to have both the petals 82 and the breech.- block 3," closed: to: block; both ends of; the,V gun, barrely as for example. during periods; of inactivity or. storage, to protect thegun barrel against. damage fromv moisture,v dirt or other; foreign matter..

Thisrnavbe accomplished; bv the opcraterV dis.- connectingtheY source ofv energy 35K and mar rually4 forcing the front tube r3 muzzle-wards after:- the empty breech has been. closed; The one-.way clutch 54.- will retain the ironttube 'lo in` its for ward position. through holding. the roda 3.9-, Thev switch zei will be closed: by the crank. 5- and theswitch 4'.' will be closed at El by the movement. orrod t9 away from the push rodi48,.a l..1z as Shown in Figure-.112'.

When it. is desiree!l toplace the gunback;intot normal'` operation, the source of energy- Bl will' belreconnected, which will automatically .Energize the clutch release solenoid'. @2f-placing 'the Betula 82y in open rposition. as4 already explained.

- It win be obvious that various modications might be made, in the device herein without da parting from theV spirit of the invention-1 We claim:

1. In; combination, a gull barrel, a breech mechanism therefor,. a. ililidrQOIltrOHEd' recoil apparatus concentric-.".vith said barrel for absorbingv the recoil'Y thereof, a sleeve extension at# taches to. said: recoil; apparatus, an outer conseil.- tric. sleeve slidablyl supported on said sleeve eg.. tension and said' recoil apparatus. for'liecitiroq catory movement, 'a pair oiA closure members; hinge means pivotaliy supporting said', closure membersv on said outer concentric sleeye, spring meansn said closure; members biasing the samev towards; a. closing position, inclined cam plates,

-9 inlsaid closure members adapted to ride on and oiisaid sleeveextensiom segmental gears on said hinge means meshing withV each other, said spring-biasingmeans, inclined cam plates and meshing segmental gears being constructed and arranged toopen and close said closure members upon reciprooatory motion of the outer concentric sleeve touncover and to cover, respectively, the muzzle end of said gun barrel, an elongated piston rod, a shock-absorbing device connecting said rod to said outer concentric sleeve, hydraulic means connected to said fluidcontrolled recoilapparatus for moving said piston rod forwardly when said gun barrel recbils, a one-way friction-brake means encircling said piston rod to permit motion ofthe same forwardly and to hold the same against motion rearwardly of the gun barrel, electrical means actuated by saidmechanism to render said oneway friction brake means inoperative to hold j' said rod against rearward movement and spring means formoving said piston rod rearwardly.

2. Inf combination, a gun barrel, a breech mechanism therefor, a fluid-controlled recoil apparatus for absorbingthe recoil of said barrel, a sleeve extension attached to said recoil apparatus; an outer concentric sleeve slidably supported on saidsleeve'extension and said recoil apparatus for reciprocatory `movement, a pair of closure members, hinge means pivotally supporting said closure members on said outer, concentric sleeve,` spring fme'ans in said closure members biasing the same towards a closing position, inclined cam plates in said'closure'members adapted to ride on and oi said sleeve extension, 'said spring-biasing means and inclined cam plates being constructed and arranged to open and close said closure members upon reciprocatory motion of the outer concentric sleeve to uncover and to cover, respectively, the muzzle end of said gunrbarrel, a rod, a device connecting said rod to said outer concentric sleeve,`hydra'ulic means connected to said fluidcontrolled recoil apparatus for moving said rod forwardly when said gun barrel recoilsbrake means cooperating with said rod to permitmotion of the same forwardly and to hold the same against 'motion rearwardly of the gun barrel, means actuated by said breech mechanism to render said brake means inoperative to hold said rod against rearward movement and means for moving said rod rearwardly.

3. In armuzzle' closure device for a gun barrel,

the combination of a sleeve xed relative `to said gun barrel,`.`an outer concentric sleeve slidably supported on said sleeve for reciprocatory movementja' pair of closure members, hinge means pivotally supportingsaid closure members on said outer concentric sleeve, spring means in said closure members biasing the same towards a closing position, inclined cam plates in said closurernembersv adapted to ride on and off said sleeve, segmental gears on said hingev means meshing with `each other, said spring-biasing means; inclined cam plates and meshing megmental gears being constructed and arranged to open and `close saidclosure members upon reciprocatory motion of the Vouter concentric sleeve-to uncover and to cover, respectively, the muzzle end of saidgun barrel, an elongated piston rod;'a shock-absorbing device connectingv said rod to said outer concentric sleeve, hydraulic means including acylinder for said piston rod to move the same when said gun barrelu recoils, a one-way friction-brake' means encircling said piston rod to permit motion of the same forwardly and to hold the same against motion rearwardly of the gun barrel, electrical means for actuating said `one-way friction brake, means to render the same inoperative to hold said rod against rearward movement and spring means for moving said piston rod rearwardly.

4. In a muzzle lclosure device for a gun barrel, the combination of a support xed relative to the gun barrel, a member reciprocably mounted on said support, closure means for the bore of said barrel and mounted on said member, means on said closure means biasing the same toward a closed position, cam means on said closure means adapted to ride on and off said support as said member reciprocates to open said closure means andto permit said'blasing means to close said closure means respectively, said closure means in the open position uncovers said bore and in the closed position covers the same,- a rod, means connecting said rod to said member, means connected to said rod for moving the same forwardly of the gun barrel, means adjacent said rod for holding the same against motion rearwardly of said gun barrel, means cooperating with said holding means for holding the same inoperative whereby said rod can be moved rearwardly and means abutting said rod for moving the same rearwardly.

' 5. In a muzzle closure devicefor a gun barrel, the combination of a support x'ed relative to the gun barrel, a member reciprocally mounted on said support, closure means for the bore of said barrel and mounted on said member, spring means on said closure means biasing the same toward a closed position, cam means on 'said means adapted to rideon and oii said support as said member reciprocates to open said closure means and to permit said biasing means to close said closure means', respectively, said closure means in theopen position uncovers said bore and in a closed position covers the same, a rod, means connecting said rod to said member, hydraulic means for moving said rod forwardly relative to the gun barrel, means for holding said rod against motion rearwardly of said gun barrel, means for rendering said holding means inoperative whereby said rod can be moved rearwardly-and means for moving said rod rearwardly. Y

f6. In a muzzle closure device for a gun barrel, the combination of a support xed `relative to the gun barrel, a member reciprocably mounted on said support, closure means for the bore of said barrel and mounted on said member, means biasing said closure means toward a closed position, means on said closure means adapted to ride 0n and off' said support as said member reciprocates to open said closure meansV and to permit said biasing'means to close lsaid closure means, respectively, said closure means in the open position uncovers said bore and in the closed position covers the same, a rod, means connecting said rod'to said member, means for moving said rod in one direction, means for holding said IL rod against motion in an opposite direction,

recoil thereof, a support fixed to said recoil apl paratus, a member reciprocably mounted in said suppQrt, closure'means for the bore of said barrely lil and mounted. on said;y member, means on. said closure means biasing thef same. towards a closed position camg means .on sa-idy closuremeans .adapted to. ride on: andi oil saidisupport ass-aid: member reciprocates. to open saidl closure means' and to permit said' biasing-means; to close said `closure means, respectively. Asaid closure; means: inthe op'enposition uncoverssaidbore and in the-.closed position covers. the; same, a rod,A means connecting said' rodi to said member, hydraulicfmeans connecting? said'. recoil apparatus: tosaidrod whereby onlrecoitoftheigun barrel fsaid= apparatus will? move said: rod `forwardly, meansfholding. said rod against motion.` rearwardly` of. saidigunfbarrel, means actuated bytheA breech mechanism torender said holding. means.: inoperative whereby said rod can. be moved rearwardly and means for moving saidrod. rearwardly;

8; A- muzzle" closure device for a gun' having a gun barrel, comprising: the combination. of. a closure means, a memberreciprocably mounted for muzzle-wardV and rearward; movement.y relativeto the gun barrel`,;means attaching saidl closure means to said'` reciprocable members means in the path of said closure means; for opening the same, means cooperatingwitn said closure means for closing the: same when moved! away from saidf opening means; means connected. to

Y said reciprocable membersfor moving the-:samer in a directionwhereby` said closure meansiare-closed, means urg-ingf saidl connecting meansy rearwardly, means holding saidl connecting means mitsmuz.- zl'e-wa-rd positic'in` against. the: force of saidurging means. means for. rendering-u said holding. means inoperativev to lioid said. connecting means-whereby the same is returned. rearwardly'by said urging. means and means to actuate said. means for rendering said holding meansinoperative..

9i. A- muzzle. closure device. for a gun having agun barrel, af recoil mechanism therefonand a breech mechanism` oni said` barrel, comprising the eomr'iinatioriv of. a closure means, amember rec-iprocably mounted for muzzle-ward and. rear war d movement. relative to the gun bart-e1; means pivotally mounting. said closure meansV upon saidreciprocable member.;V means in` the path oisaid closure means'y for opening the same, means co.- operating with.r said closure means7 for closing the same when moved' away froml said* opening. means, hydraulicallyloperated: means. connected to the gun recoil mechanism: and said reciprocable member' forinoving the same: in a muzzle-ward direction: whereby Said. closure` means. are` closed, resilient means urging4 saidy hydraulically-operatedmeans rearwardly, friction means` associated with said hydraulically-operated means for hold ingl the same in its` muzzle-ward position againsttheurging` force. of-A said resilient means,- meansA for renderingV said frictionf means inoperative. to hold said hydraulically-operated. means whereby the same isreturned'. rearwardly by said; resilient means and means! operatediin timed-,reiationwith the breech mechanism` to actuate said. means for rendering said'. ffii'cticmA means inoperative.

150;. In combination, a. gun', barrel, a` breech. mechanism therefor, a fluid-controlled recoil. apparatus f or absorbing: therecoil ot the gun barret. closure members for the barret boreg, a member reciprocably mounted forf muzzle-ward; and! rear.-- ward movement relativef to the gunrbarrel, means pivotally mounting said closure members upon'. said reciprocable member', means in the path of said closure-membersior opening the-same; means cooperating with said closure. members for' clos.- in'g thesame when movedawa-yv from said; open.-

ingt means, hydraulically-operated means connectedtoV said gun recoil mechanism and said reciprocable member for moving the same inf a muzzle-ward directionwher-eby said closure mem.- bers are closed, resilient means urging said hydraulically-operated means rearwardly, friction means associated. with. saidv hydraulically-operated,Y meansv for holding the same inV its muzzleward position against the urging, force; of said resilient means, means for rendering said frictionzmeans inoperative to hold said hydraulicallyoperated means whereby the same. is returned rearwardly bysaid resilient means andl means operated in timed. relationship by the.- breech mechanism toactuate said. means for rendering said firictionmeans inoperative.

1i. A muzzle closure device for. a gun barrel comprising the combination. of a meansA adapted to cover anduncover the muzzle of the gunbarrel, means associated withsaid first-namedl means for supporting the same in cooperative. relationship' with. the gunbarrel, means for actuating sa-idfirst-named means to a position to cover the muzzle, means opposing the movement of said actuating means, means adjacent said actuating means for holding the same in a covering position for thegun barrel muzzle, andV means abutting said.` holding means for rendering the same inoperative. whereby saidI opposing means return said actuating means to ap'osition' to uncover' saidgun muzzle.

12. A muzzle closure device for a gun barrel comprising the combination of a means adapted toV cover and uncover the muzzle of thegun barrel, means associated with said first-named means for supporting the: same in cooperative relationship'with' the gun barrel, hydraulically-operated means for actuating said first-named means to a position to cover the gun muzzle resilient means. opposing the'movement of said actuating means, frictionV brakel means adjacent said actuati-ng.r means for holding thev same'in a covering position for the gun barrel muzzle, means abutting said friction brakemeans for rendering the same inoperativek whereby said resilientmeans will. return said actuating means. toY a position to uncover said gun muzzle.

13;. In. combination, a gun barrel', a breech mechanism. therefor, a hydraulic recoil system attached. to said gun barrel for absorbing the shock of recoil'. thereof, means' adapted to cover and uncover the muzzle ofthe gun barrel, means associated with said iirstnamed: means for slidably' supporting the same in cooperativev relationship with the gun barrel, hydraulically-operated means connectedy to said recoil system forv actuating said first-named means to a position to cover the gun muzzle, resilient means opposing the movement of said' actuating means, frictionbrake means adjacent said actuating means for holding the same in a covering position for the gun barrel muzzle, means abutting said friction brake meansV for rendering.' the same inoperative whereby said' resilient means will return said actuating means to a position to uncover said' gun muzzle and means activated by said breech mechanism for energizing said abutting' means.

14. In combination, a gun barrel', a hydraulic recoil system for absorbing recoil of saidy gun barrel, a closure means for" said gun barrel bore, operating means connected to said recoil system to open and close said closure means, means connected with said operating means to' cause the same to hold' said' closure means in. an open posi'- tion, meansi associated with said' holding means to render the same ineffective and means after said last mentioned means has become ineffe; tive for returning said operating means to a position to cause said closure means to close.

15. In combination, a gun barrel, a breech mechanism therefor, a hydraulic recoil system for absorbing recoil of said gun barrel, a closure means for the gun barrel bore, hydraulicallyoperated means actuated by said recoil system when the gun barrel moves in recoil to open and close said closure means, means connected with said hydraulically-operated means whereby the same is adapted to hold said closure means in an open position, electromagnetic means associated with said holding means adapted upon being energized to render the same ineiective, means after said last-mentioned means has become ineiective to return said hydraulically-operated means to a position to cause said closure means to close and means operated by said breech mechanism to energize said electromagnetic means.

16. In combination, a gun barrel, a breech mechanism therefor, a hydraulic recoil system for absorbing recoil of said gun barrel, a closure means for the gun barrel bore, hydraulicallyoperated means actuated by said recoil system when the gun barrel moves rearwardly in recoil to open and close said closure means, a one-way friction brake means connected with said hydraulically-operated means to cause the same to hold said closure means in an open position, electromagnetic means associated with said holding means adapted upon being energized to render the same ineffective, and means after said lastmentioned means has become ineffective to return said operating means to a position to cause said closure means to close and means operated by said breech mechanism when in a closed position to energize said electromagnetic means.

17. In combination, a gun barrel, a breech mechanism therefor and adapted to open and close to receive a round of ammunition, closure means for the bore of the gun barrel, means actuated with the firing of the round of ammunition in said gun barrel to cause said closure means to close said bore after a predetermined time interval has elapsed after the firing of the round of ammunition, means associated with said actuating means for locking the same in a bore closing position, and means actuated by the breech mechanism when in a closed position to render said locking means ineective and Whereby said closure means opens said gun barrel bore.

' ALEXANDER E. KRAMER.

VICTOR F. LUCHT. 

